At 50 years old, Phil Mickelson is the oldest 54-hole leader in PGA Championship history.
Mickelson joins just two other players – Greg Norman and Tom Watson – as players age 50 or older to have held the 54-hole lead at a major in the last 30 years.
Norman was 53 years old when he had a two-stroke 54-hole lead in the 2008 Open Championship at Royal Birkdale. Norman would finish in a tie for third there after a final-round 77, finishing six behind the winner, Padraig Harrington.
Watson was 59 years old when he had a one-stroke 54-hole lead a year later in the 2009 Open Championship at Turnberry. Watson would lose in a playoff to Stewart Cink.
Mickelson will try to be the first 50-something to win a major on Sunday, taking a one-stroke lead into the final round over Brooks Koepka.
The oldest major winner in history is Julius Boros. He won the 1968 PGA Championship when he was 48 years old.